Fix potential clash with reserved keywords

Note:
* This also changes the constructor semantics
  when multiple oneof-values are given (now the *first*
  value is kept instead of the last)

* Using reserved keywords as protobuf field-names remains
  a bad idea regardless. For example a field called `delete`
  will break ts-proto / protoc-gen-js and probably others

spec/fixtures/test.pb.cr

@@ -15,9 +15,7 @@ struct Test
     required :sint64, :sint64, 13
     required :bool, :bool, 14
 
-    # "enum" is a reserved keyword in
-    # crystal so we use "my_enum" for this one
-    repeated :my_enum, SomeEnum, 15
+    repeated :enum, SomeEnum, 15
 
     required :fixed64, :fixed64, 16
     required :sfixed64, :sfixed64, 17

spec/fixtures/test3.pb.cr

@@ -25,7 +25,7 @@ module TestMessagesV3
       optional :sint32, :sint32, 12
       optional :sint64, :sint64, 13
       optional :bool_e, :bool, 14
-      repeated :my_enum, SomeEnum, 15
+      repeated :enum, SomeEnum, 15
       optional :fixed64, :fixed64, 16
       optional :sfixed64, :sfixed64, 17
       optional :double, :double, 18

spec/protobuf/message_spec.cr

@@ -29,7 +29,7 @@ describe Protobuf::Message do
       test.sint64.should eq(-9223372036854775808)
       test.bool.should eq true
 
-      test.my_enum.should eq [SomeEnum::YES, SomeEnum::NO, SomeEnum::NEVER]
+      test.enum.should eq [SomeEnum::YES, SomeEnum::NO, SomeEnum::NEVER]
 
       test.fixed64.should eq 4294967296
       test.sfixed64.should eq 2147483648
@@ -62,7 +62,7 @@ describe Protobuf::Message do
 
   it "handles oneof in proto2" do
     # When multiple oneof values are populated
-    # by the ctor only the last survives
+    # by the ctor only the first survives
     msg = TestMessagesProto2::TestOneof1.new(
       a: 1,
       oo0_a: 2, oo0_b: 3, oo0_c: 4,
@@ -71,23 +71,23 @@ describe Protobuf::Message do
     )
 
     payload = [ msg.a, msg.oo0_a, msg.oo0_b, msg.oo0_c, msg.b, msg.oo1_a, msg.oo1_b, msg.oo1_c ]
-    payload.should eq([1, nil, nil, 4, 5, nil, nil, 8])
+    payload.should eq([1, 2, nil, nil, 5, 6, nil, nil])
 
     # `msg.foo` tells us the string name
     # of the member `foo` that is set
-    msg.oo0.should eq("oo0_c")
-    msg.oo1.should eq("oo1_c")
+    msg.oo0.should eq("oo0_a")
+    msg.oo1.should eq("oo1_a")
 
     # Setting values outside of oneof's leaves the oneof's untouched
     msg.a = 1
     msg.b = 5
     payload = [ msg.a, msg.oo0_a, msg.oo0_b, msg.oo0_c, msg.b, msg.oo1_a, msg.oo1_b, msg.oo1_c ]
-    payload.should eq([1, nil, nil, 4, 5, nil, nil, 8])
+    payload.should eq([1, 2, nil, nil, 5, 6, nil, nil])
 
     # Setting a oneof value resets the others in the same oneof
     msg.oo0_b = 3
     payload = [ msg.a, msg.oo0_a, msg.oo0_b, msg.oo0_c, msg.b, msg.oo1_a, msg.oo1_b, msg.oo1_c ]
-    payload.should eq([1, nil, 3, nil, 5, nil, nil, 8])
+    payload.should eq([1, nil, 3, nil, 5, 6, nil, nil])
     msg.oo0.should eq("oo0_b")
 
     msg.oo1_b = 7
@@ -99,7 +99,7 @@ describe Protobuf::Message do
 
   it "handles oneof in proto3" do
     # When multiple oneof values are populated
-    # by the ctor only the last survives
+    # by the ctor only the first survives
     msg = TestMessagesProto3::TestOneof1.new(
       a: 1,
       oo0_a: 2, oo0_b: 3, oo0_c: 4,
@@ -108,23 +108,23 @@ describe Protobuf::Message do
     )
 
     payload = [ msg.a, msg.oo0_a, msg.oo0_b, msg.oo0_c, msg.b, msg.oo1_a, msg.oo1_b, msg.oo1_c ]
-    payload.should eq([1, nil, nil, 4, 5, nil, nil, 8])
+    payload.should eq([1, 2, nil, nil, 5, 6, nil, nil])
 
     # `msg.foo` tells us the string name
     # of the member `foo` that is set
-    msg.oo0.should eq("oo0_c")
-    msg.oo1.should eq("oo1_c")
+    msg.oo0.should eq("oo0_a")
+    msg.oo1.should eq("oo1_a")
 
     # Setting values outside of oneof's leaves the oneof's untouched
     msg.a = 1
     msg.b = 5
     payload = [ msg.a, msg.oo0_a, msg.oo0_b, msg.oo0_c, msg.b, msg.oo1_a, msg.oo1_b, msg.oo1_c ]
-    payload.should eq([1, nil, nil, 4, 5, nil, nil, 8])
+    payload.should eq([1, 2, nil, nil, 5, 6, nil, nil])
 
     # Setting a oneof value resets the others in the same oneof
     msg.oo0_b = 3
     payload = [ msg.a, msg.oo0_a, msg.oo0_b, msg.oo0_c, msg.b, msg.oo1_a, msg.oo1_b, msg.oo1_c ]
-    payload.should eq([1, nil, 3, nil, 5, nil, nil, 8])
+    payload.should eq([1, nil, 3, nil, 5, 6, nil, nil])
     msg.oo0.should eq("oo0_b")
 
     msg.oo1_b = 7

src/protobuf/generator.cr

@@ -255,6 +255,11 @@ end
 
 module Protobuf
   class Generator
+    # Turns `foo/bar/batz.proto` into `foo_bar_batz.pb.cr`
+    def self.output_filename(path)
+      path.split(".")[0..-2].join("").gsub(File::SEPARATOR, "_") + ".pb.cr"
+    end
+
     def self.compile(req)
       raise Error.new("no files to generate") if req.proto_file.nil?
       package_map = {} of String => String
@@ -266,7 +271,7 @@ module Protobuf
       files = req.proto_file.not_nil!.map do |file|
         generator = new(file, package_map)
         CodeGeneratorResponse::File.new(
-          name: File.basename(file.name.not_nil!, ".proto") + ".pb.cr",
+          name: output_filename(file.name.not_nil!),
           content: generator.compile
         )
       end
@@ -291,7 +296,7 @@ module Protobuf
         puts nil
 
         unless @file.dependency.nil?
-          @file.dependency.not_nil!.each { |dp| puts "require \"./#{File.basename(dp.not_nil!, ".proto") + ".pb.cr"}\"" }
+          @file.dependency.not_nil!.each { |dp| puts "require \"./#{self.class.output_filename(dp.not_nil!)}\"" }
           puts nil
         end
 

src/protobuf/message.cr

@@ -152,7 +152,7 @@ module Protobuf
         {% end %}
       )
         {% for tag, field in FIELDS %}
-          self.{{field[:name].id}} = {{field[:name].id}}
+          self.{{field[:name].id}} = @{{field[:name].id}}
         {% end %}
       end
     end